2000 Banshee Only running on right cylinder!

[kwchico]

just pick up a 2000 banshee. So far I have cleaned carbs twice. changed plugs. and still only the right cylinder runs.

Compression in both cylinder are 115psi. The right cylinder looks really clean through the spark plug hole. I can see the numbers stamped on the piston. I seen a 658 or a 685. I only seen three numbers, there were a couple more. The left cylinder looked really dirty and black, Looked wet too. The right running cylinder had a really good spark plug color. The left plug looked black and wet. electrode had a slight purple tint to it? Changed both with brand new plugs, same outcome.

I also tried swapping coils. Same outcome.

 

While runnning. I try to get the left cylinder to run by spraying a little fluid in the carb. nothing. it just bogs down the running cylinder.

So its not gas or spark, and compression is 115??? WTF??

Is it possible to have a bad piston with good compression?

 

The quad is also modded. It has dual keinen 34mm carbs. big guns exhaust. k and n filters and that throttle cable mod.

Cylinder jug is stock. stock head.

 

So what do you guys think??

 

If it has compression spark and gas shouldnt it fire??

[Trenton Tigney]

Pull the jugs off an inspect the right cylinder pistons , I had the same problem except mine was the left cylinder. It could be the rings as well just tear the jugs off so you can fully inspect them.

[fappy'97]

ETA- never mind. I know nothing.

Edited October 5, 2013 by rappy'97

[kwchico]

So there is a possiblity the piston is bad even with 115psi? 

 

Just to clear things up, the problem cylinder is the left one.

 

 

I really dont want to tear it down and find out a piston is bad.

 

I think it should run with that compression? WTH

[Trenton Tigney]

It should , but until you tear into you really don't know. Take the exhaust or reeds off an look into them to see what the side of the pistons look ( the rings ) before you take the jugs off.

[kwchico]

tomorrow I am going to remove exhaust and reeds. and have a look at the walls.

 

I felt a little bit of air coming out of the end of the left side exhaust tip. 

the right cylinder runs great, but it still hard to start without some starting fluid. 

 

with these keinen carbs, what should the screws be set at??????? it has open filters.

 

would someone put keinen carbs on a stock bore size??

[kwchico]

also, i noticed that when i reved the engine, some oil came out of this hole on the back top of the egnine?? Transmission oil? Maybe it was too full? I added maybe too much?

[kwchico]

also. on the carb that is running, i feel the air being sucked in,

 

but on the the left side that isnt running, i actaully feel air being blown out?????

[sheerider11]

also. on the carb that is running, i feel the air being sucked in,

 

but on the the left side that isnt running, i actaully feel air being blown out?????

That sounds like bad reeds

[kwchico]

how can I tell if the reeds are bad?

 

Dont you need aftermarket reed cages to run the bigger keihen carbs??

 

I also have a boost bottle bridging the two manifolds together.

[Trenton Tigney]

Take the reeds off an look through the flaps an see if you see light showing

[oldskool]

Pull carb off, then pull intake off, then pull reed cage out and check pedals for cracks or broken reeds. The reeds should snap shut and prevent air/exhaust/gas mixture from flowing back through carb.

[kwchico]

ok. so with bad reeds the cylinder wont fire at all?

 

I would think it would at least run, just not as good?

 

air blowing out of carbs is a sure sign???

 

Im going to flip reed pedals tomorrow.

[kwchico]

but why when i try to spray gas in the carb of the non running cylinder while the other cylinder is running, it bogs down the running cylinder?? 

[Trenton Tigney]

Do what oldskool said , if there fine an can't see air through them or any damage.